Folia Historico-Naturalia Musei Matraensis - A Mátra Múzeum Természetrajzi Közleményei 6. (1980)

Domokos, T.: Adatok az Anisus vortex L. faj morfometriájához

Fol. Hist.-nat. Mus. \Tatr

. 6.1980. DATA TO THE MORPHOMETRY OF THE SPECIES ANISUS YORTEX (L.) (GASTROPODA, PLANORBIDAE) DOMOKOS Tamás Munkácsy Mihály Múzeum, Békéscsaba Abstract: The biometry of Anisus vortex (L.): radial growth does riot follow a logarithmic spiral but a power function. Up to whorl-numbers 4 or 5, with the 25-individual groups the deviation of the mode of the Balatonmária material is about 5 p. c. With Anisus vortex the growth-lines smaller in number than with Anisus septemgyratus. Introduction —- Several papers deal with cell-morphology and anatomy of the family Planorbidae (WAGNER, 1929; SOÓS, 1935; HUBENDICK, 1951; PARAENSE, 1956; SCHUTTE—EEDEN, 1959; FRANCK—MEYLING, 1966; HUDEC, 1967; DOMOKOS, 1976, 1977, 1978). The morphology of the Anisus genus was studied more circumstantially by HUBENDICK (1951), HUDEC (1967) and DOMOKOS (1977, 1978). I have been studying the whorl-growth for years: the biometry of Anisus septemgyratus was published in two papers (DOMOKOS, 1977, 1978). The results were compiled form literary data (WAGNER, 1929; THOMPSON, 1942; FRANCK—MEYLING, 1966), by means of a geometrical, or more precisely graphical evaluation, having presumed the theory of a growth according to a logarithmic spiral. [R

n

=R

1

e 2ят

(

п

—D where R

n is the radius of the n

th

, R

x that of the first whorl, in a polar system of co-ordinates, m = constant, the value characteristic to the genus (Fig.l).] By controlling the results it was proved that the growth does not follow a logarithmic spiral as presumed earlier by WAGNER. I tried to save the logarithmic evaluation by splitting up the function log lor — K(r = R, K = = WN = whorl number) into straight sections. Thus the results up to now are only of approximate character and can be regarded merely as an expedient. In reality, the two sections of growth are not separate, one passing gradually into the other. Thus, did I begin to study the species Anisus vortex L. Having amassed a sufficient quantity of individuals for statistical studies (from two biotopes, both populations come from the southern shore of Lake Balaton) I proceeded. 1. loc. -.Balatonmária 2. loc. : Szántód dat.: 15. 07. 1961 dat:. 11. 07. 1976 leg., det. : Á. KÁROLYI leg., det. : T. DOMOKOS sample: 100 sample :59 Thanks are due to Dr. ANDOR RICHNOVSZKY for the Balatonmária sample. 175